According to the Glossary of Prosthodontics Terms, a fixed dental prosthesis is any dental prosthesis that is luted, screwed or mechanically attached or otherwise securely retained to teeth or dental implants that furnish its primary support. The shape of this kind of dental prostheses depends on the geometry of the tooth that it's replacing due to its multiplicity of concavities and convexities. The connector area between each tooth demands special requirements since it's the area with the highest stresses during mastication, with loads that may reach SOON, or even 1000 N in mastication peaks. The stress values generated in these connectors are highest in a cantilever bridge, i.e. a bridge that is retained and supported only on one end by one or more abutment(s), when compared to a conventional dental bridge. Actually, to optimize the design of a fixed dental prostheses in a functional and esthetic rehabilitation, it's possible to combine engineering techniques and the new computer-aided-design/computer-aided-manufacturing systems (CAD-CAM) applied to Dental Medicine. In this work it is described a methodology to optimize the geometry and connection of a cantilever bridge in a fixed dental prosthesis, by means of experimental and numeric techniques, like photoelasticity and finite element meshes, respectively. In the work here described a CAD-CAM dental system (Kavo (R) Everest) was used to create a FDP with 4 teeth representing a conventional bridge and a cantilever bridge. The .igs file generated with this software had been converted to a Solidworks file in order to make a longitudinal cut of the structure. That design was augmented 10 times in order for being cutted on a photoelastic template and easily analyzed. The geometric model was also used to generate a FEM in the code ABAQUS. The obtained results are similar to those of other authors, like Anusavice and Oh. Highest stresses are verified in the gingival embrasure of the connector, specially the one related to the cantilever, while deformation occurs mainly in the occlusal embrasure. The introduction of a fillet on the connector area of the CAD design helps reducing the stresses generated in this area. The stress distribution in the experimental and numerical model was similar, and validated by Tresca criteria. We can conclude that fillet introduction is crucial to reduce the stresses in the connector area that may cause a catastrophic failure of the dental rehabilitation. CAD-CAM dental software should have this kind of design functions just like CAD-CAM engineering software.
|Title of host publication||Biodental Engineering|
|Number of pages||3|
|Publication status||Published - 2010|
|Event||1st International Conference on Biodental Engineering - Porto, Portugal|
Duration: 26 Jun 2009 → 27 Jun 2009
|Conference||1st International Conference on Biodental Engineering|
|Period||26/06/09 → 27/06/09|